Take-all disease is a serious problem in the production of cereals, particularly wheat and barley. It is caused by the soil-borne fungus Gaeumannomyces graminis (Gg). The fungus infects the roots of the plant, and grows throughout the root tissue, causing a black rot. The growth of the fungus in the roots and lower stem prevents the plant from obtaining sufficient water and/or nutrients from the soil, and is manifested as poor plant vigor and, in severe instances of disease, by the formation of "whiteheads," which are barren or contain few, shriveled grains. Yield losses result. Gaeumannomyces species also infect other cereal crops, for example, rice and oats; and turf.
Currently the primary means of avoiding crop loss due to infestation of the soil by Gg has been to rotate the crop grown to one which is resistant to Gg. However, in areas where the primary crops are cereals, rotation is not a desirable practice, and an effective control agent is greatly desired.
It is an object of this invention to provide an effective method for control of Take-all disease in plants. It is a further object of this invention to provide compounds that control the growth of Gg in the soil so as to reduce crop loss. It is still a further object of this invention to provide fungicidal compositions that may be used for control of Take-all disease.
SUMMARY OF THE INVENTION
The present invention provides a method of controlling disease caused by Gaeumannomyces species in plants comprising applying to the plant locus, that is, the plant itself, its seed, or the soil, a fungicidally effective amount of a fungicide of the formula ##STR2## wherein Z.sub.1 and Z.sub.2 are C or N and are part of an aromatic ring selected from benzene, pyridine, thiophene, furan, pyrrole, pyrazole, thiazole, and isothiazole;
A is selected from --C(X)-amine, --C(O)--SR.sub.3, --NH--C(X)R.sub.4, and --C(.dbd.NR.sub.3)--XR.sub.7 ; PA1 B is --W.sub.m --Q(R.sub.2).sub.3 or selected from o-tolyl, 1-naphthyl, 2-naphthyl, and 9-phenanthryl, each optionally substituted with halogen or R.sub.4 ; PA1 Q is C, Si, Ge, or Sn; PA1 W is --C(R.sub.3).sub.p H.sub.(2-p) --; or when Q is C, W is selected from --C(R.sub.3).sub.p H.sub.(2-p) --, --N(R.sub.3).sub.m H.sub.(1-m) --, --S(O).sub.p --, and --O--; PA1 X is O or S; PA1 n is 0, 1, 2, or 3; PA1 m is 0 or 1; PA1 p is 0, 1, or 2; PA1 each R is independently selected from PA1 a) halo, formyl, cyano, amino, nitro, thiocyanato, isothiocyanato, trimethylsilyl, and hydroxy; PA1 b) C1-C4 alkyl, alkenyl, alkynyl, C3-C6 cycloalkyl, and cycloalkenyl, each optionally substituted with halo, hydroxy, thio, amino, nitro, cyano, formyl, phenyl, C1-C4 alkoxy, alkylcarbonyl, alkylthio, alkylamino, dialkylamino, alkoxycarbonyl, (alkylthio)carbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylsulfinyl, or alkylsulfonyl; PA1 c) phenyl, furyl, thienyl, pyrrolyl, each optionally substituted with halo, formyl, cyano, amino, nitro, C1-C4 alkyl, alkenyl, alkynyl, alkoxy, alkylthio, alkylamino, dialkylamino, haloalkyl, and haloalkenyl; PA1 d) C1-C4 alkoxy, alkenoxy, alkynoxy, C3-C6 cycloalkyloxy, cycloalkenyloxy, alkylthio, alkylsulfinyl, alkylsulfonyl, alkylamino, dialkylamino, alkylcarbonylamino, aminocarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, alkylcarbonyl, alkylcarbonyloxy, alkoxycarbonyl, (alkylthio)carbonyl, phenylcarbonylamino, phenylamino, each optionally substituted with halo; PA1 wherein two R groups may be combined to form a fused ring; PA1 each R.sub.2 is independently selected from alkyl, alkenyl, alkynyl, cycloalkyl, cycloalkenyl and phenyl, each optionally substituted with R.sub.4 or halogen; and wherein, when Q is C, R.sub.2 may also be selected from halo, alkoxy, alkylthio, alkylamino, and dialkylamino; PA1 wherein two R.sub.2 groups may be combined to form a cyclo group with Q; PA1 R.sub.3 is C1-C4 alkyl; PA1 R.sub.4 is C1-C4 alkyl, haloalkyl, alkoxy, alkylthio, alkylamino, or dialkylamino; PA1 R.sub.7 is C1-C4 alkyl, haloalkyl, or phenyl, optionally substituted with halo, nitro, or R.sub.4 ; PA1 or an agronomic salt thereof.
The term "amine" in --C(X)-amine means an unsubstituted, monosubstituted, or disubstituted amino radical, including nitrogen-bearing heterocycles. Examples of substituents for the amino radical include, but are not limited to, hydroxy; alkyl, alkenyl, and alkynyl, which may be straight or branched chain or cyclic; alkoxyalkyl; haloalkyl; hydroxyalkyl; alkylthio; alkylthioalkyl; alkylcarbonyl; alkoxycarbonyl; aminocarbonyl; alkylaminocarbonyl; cyanoalkyl; mono- or dialkylamino; phenyl, phenylalkyl or phenylalkenyl, each optionally substituted with one or more C1-C6 alkyl, alkoxy, haloalkyl, C3-C6 cycloalkyl, halo, or nitro groups; C1-C4 alkyl or alkenyl groups substituted with heterocycles, optionally substituted with one or more C1-C4 alkyl, alkoxy, haloalkyl, halo, or nitro groups. Examples of such nitrogen-bearing heterocycles, which are bonded at a nitrogen to --C(X)--, include, but are not limited to, morpholine, piperazine, piperidine, pyrrole, pyrrolidine, imidazole, and triazoles, each of which may be optionally substituted with one or more C1-C6 alkyl groups.
Specific examples of the amino radicals useful in the present invention include, but are not limited to, ethylamino, methylamino, propylamino, 2-methylethylamino, 1-propenylamino, 2-propenylamino, 2-methyl-2-propenylamino, 2-propynylamino, butylamino, 1,1-dimethyl-2-propynylamino, diethylamino, dimethylamino, N-(methyl)ethylamino, N-(methyl)-1,1-(dimethyl)ethylamino, dipropylamino, octylamino, N-(ethyl)-1-methylethylamino, 2-hydroxyethylamino, 1-methylpropylamino, chloromethylamino, 2-chloroethylamino, 2-bromoethylamino, 3-chloropropylamino, 2,2,2-trifluoroethylamino, cyanomethyl, methylthiomethylamino, (methylsulfonyl)oxyethylamino, 2-ethoxyethylamino, 2-methoxyethylamino, N-(ethyl)-2-ethoxyethylamino, 1-methoxy-2,2-dimethylpropylamino, cyclopropylamino, cyclobutylamino, cyclopentylamino, cyclohexylamino, methoxymethylamino, N-(methoxymethyl)ethylamino, N-(1-methylethyl)propylamino, 1-methylheptylamino, N-(ethyl)-1-methylheptylamino, 6,6-dimethyl-2-hepten-4-ynylamino, 1,1-dimethyl-2-propynylamino. Further examples include benzylamino, ethylbenzylamino, 3-methoxybenzylamino, 3-(trifluoromethyl)benzylamino, N-methyl-3-(trifluoromethyl)benzylamino, 3,4,5-trimethoxybenzylamino, 1,3-benzodioxol-5-ylmethylamino, phenylamino, 3-(1-methylethyl)phenylamino, ethoxyphenylamino, cyclopentylphenylamino, methoxyphenylamino, nitrophenylamino, 1-phenylethylamino, N-(methyl)-3-phenyl-2-propenylamino, benzotriazolylphenylmethyl, 2-pyridinylmethylamino, N-(ethyl)-2-pyridinylmethylamino, 2-thienylmethylamino, and furylmethylamino. Further examples of amino radicals include methylhydrazino, dimethylhydrazino, N-ethylanilino, and 2-methylanilino. The amine may also be substituted with diethyl N-ethylphosphoramidic acid, t-butoxycarbonyl, methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, etc. of these examples of the amino radical, ethylamino is preferred.
Examples of B include, but are not limited to, trimethylsilyl, ethyldimethylsilyl, diethylmethylsilyl, triethylsilyl, dimethylpropylsilyl, dipropylmethylsilyl, dimethyl-1-(methyl)ethylsilyl, tripropylsilyl, butyldimethylsilyl, pentyldimethylsilyl, hexyldimethylsilyl, cyclopropyldimethylsilyl, cyclobutyldimethylsilyl, cyclopentyldimethylsilyl, cyclohexyldimethylsilyl, dimethylethenylsilyl, dimethylpropenylsilyl, chloromethyldimethylsilyl, 2-chloroethyldimethylsilyl, bromomethyldimethylsilyl, bicycloheptyldimethylsilyl, dimethylphenylsilyl, dimethyl-2-(methyl)phenylsilyl, dimethyl-2-fluorophenylsilyl, and other such silyl groups of the formula Si(R.sub.2).sub.3 ; any such silyl group connected to the Z.sub.1 -Z.sub.2 ring by a methylene group; and any of these groups wherein germanium or tin is substituted for silicon. Of these examples of B, trimethylsilyl is preferred.
Further examples of B include 1,1-dimethylethyl, 1,1-dimethylpropyl, 1,1-dimethylbutyl, 1,1-dimethylpentyl, 1-ethyl-1-methylbutyl, 2,2-dimethylpropyl, 2,2-dimethylbutyl, 1-methyl-1-ethylpropyl, 1,1-diethylpropyl, 1,1,2-trimethylpropyl, 1,1,2-trimethylbutyl, 1,1,2,2-tetramethylpropyl, 1,1-dimethyl-2-propenyl, 1,1,2-trimethyl-2-propenyl, 1,1-dimethyl-2-butenyl, 1,1-dimethyl-2-propynyl, 1,1-dimethyl-2-butynyl, 1-cyclopropyl-1-methylethyl, 1-cyclobutyl-1-methylethyl, 1-cyclopentyl-1-methylethyl, 1-(1-cyclopentenyl)-1-methylethyl, 1-cyclohexyl-1-methylethyl, 1-(1-cyclohexenyl)-1-methylethyl, 1-methyl-1-phenylethyl, 1,1-dimethyl-2-chloroethyl, 1,1-dimethyl-3-chloropropyl, 1,1-dimethyl-2-methoxyethyl, 1,1-dimethyl-2-(methylamino)ethyl, 1,1-dimethyl-2-(dimethylamino)ethyl, 1,1-dimethyl-3-chloro-2-propenyl, 1-methyl-1-methoxyethyl, 1-methyl-1-(methylthio)ethyl, 1-methyl-1-(methylamino)ethyl, 1-methyl-1-(dimethylamino) ethyl, 1-chloro-1-methylethyl, 1-bromo-1-methylethyl, and 1-iodo-1-methylethyl. Of these examples of B, 1,1-dimethylethyl is preferred.
Further examples of B are 1,1-dimethylethylamino, 1,1-dimethylpropylamino, 1,1-dimethylbutylamino, 1,1-dimethylpentylamino, 1-ethyl-1-methylbutylamino, 2,2-dimethylpropylamino, 2,2-dimethylbutylamino, 1-methyl-1-ethylpropylamino, 1,1-diethylpropylamino, 1,1,2-trimethylpropylamino, 1,1,2-trimethylbutylamino, 1,1,2,2-tetramethylpropylamino, 1,1-dimethyl-2-propenylamino, 1,1,2-trimethyl-2-propenylamino, 1,1-dimethyl-2-butenylamino, 1,1-dimethyl-2-propynylamino, 1,1-dimethyl-2-butynylamino, 1-cyclopropyl-1-methylethylamino, 1-cyclobutyl-1-methylethylamino, 1-cyclopentyl-1-methylethylamino, 1-(1-cyclopentenyl)-1-methylethylamino, 1-cyclohexyl-1-methylethylamino, 1-(1-cyclohexenyl)-1-methylethylamino, 1-methyl-1-phenylethylamino, 1,1-dimethyl-2-chloroethylamino, 1,1-dimethyl-3-chloropropylamino, 1,1-dimethyl-2-methoxyethylamino, 1,1-dimethyl-2-(methylamino)-ethylamino, 1,1-dimethyl-2-(dimethylamino)ethylamino, and 1,1-dimethyl-3-chloro-2-propenylamino. Any of these groups may also have a methyl substitution on the nitrogen, as in N-(methyl)-1,1-dimethylethylamino and N-(methyl)-1,1-dimethylpropylamino. Of these examples of B, 1,1-dimethylethylamino and N-(methyl)-1,1-dimethylethylamino are preferred.
Further examples of B include 1,1-dimethylethoxy, 1,1-dimethylpropoxy, 1,1-dimethylbutoxy, 1,1-dimethylpentoxy, 1-ethyl-1-methylbutoxy, 2,2-dimethylpropoxy, 2,2-dimethylbutoxy, 1-methyl-1-ethylpropoxy, 1,1-diethylpropoxy, 1,1,2-trimethylpropoxy, 1,1,2-trimethylbutoxy, 1,1,2,2-tetramethylpropoxy, 1,1-dimethyl-2-propenoxy, 1,1,2-trimethyl-2-propenoxy, 1,1-dimethyl-2-butenoxy, 1,1-dimethyl-2-propynyloxy, 1,1-dimethyl-2-butynyloxy, 1-cyclopropyl-1-methylethoxy, 1-cyclobutyl-1-methylethoxy, 1-cyclopentyl-1-methylethoxy, 1-(1-cyclopentenyl)-1-methylethoxy, 1-cyclohexyl-1-methylethoxy, 1-(1-cyclohexenyl) -1-methylethoxy, 1-methyl-1-phenylethoxy, 1,1-dimethyl-2-chloroethoxy, 1,1-dimethyl-3-chloropropoxy, 1,1-dimethyl-2-methoxyethoxy, 1,1-dimethyl-2-(methylamino)ethoxy, 1,1-dimethyl-2-(dimethylamino)ethoxy, 1,1-dimethyl-3-chloro-2-propenoxy. Of these examples of B, 1,1-dimethylethoxy is preferred.
Further examples of B include 1-methylcyclopropyl, 1-methylcyclobutyl, 1-methylcyclopentyl, 1-methylcyclohexyl, 1-methylcyclopropylamino, 1-methylcyclobutylamino, 1-methylcyclopentylamino, 1-methylcyclohexylamino, N-(methyl)-1-methylcyclopropylamino, N-(methyl)-1-methylcyclobutylamino, N-(methyl)-1-methylcyclopentylamino, and N-(methyl)-1-methylcyclohexylamino.
R.sub.n may be any substituent(s) which do(es) not unduly reduce the effectiveness of the compounds to function in the method of disease control. R.sub.n is generally a small group; "n" is preferably 1 for benzene rings and 2 for furan and thiophene. R is more preferably methyl or halogen, and more preferably is located adjacent to A.
The present invention also provides novel compounds of the formula given above. However, when Z.sub.1 and Z.sub.2 are part of a benzene ring, the following are not included as novel compounds: 1) n is not zero when B is trimethylsilyl and A is N,N-diethylaminocarbonyl, N,N-bis(1-methylethyl)aminocarbonyl, N-methylaminothiocarbonyl, N-ethylaminocarbonyl, 1-piperidinylcarbonyl, or N-phenylaminocarbonyl; or when B is orthotolyl and A is N,N-diethylaminocarbonyl, N,N-bis(1-methylethyl)aminocarbonyl, N-methylaminocarbonyl, or O-methylcarbamyl; or when B is 1,1-dimethylethyl and A is N,N-dimethylaminothiocarbonyl or N-phenylaminocarbonyl; or when B is trimethylstannyl and A is N,N-diethylaminocarbonyl or O-(1,1-dimethylethyl)carbamyl; 2) when B is 2-trimethylsilyl and A is N,N-diethylaminocarbonyl, R.sub.n is not 3-fluoro-6-formyl, 3-fluoro-6-methyl, 3-chloro-6-formyl, 3-fluoro, 3-chloro, 3-chloro-6-methyl, 6-trimethylsilyl, or 6-methyl; 3) when A is O-(1,1-dimethylethyl)carbamyl and B is 2-trimethylsilyl, R.sub.n is not 5-trifluoromethyl; 4) when A is N-phenylaminocarbonyl and B is 2,2-dimethylpropyl, R.sub.n is not 3-methyl; and 5) R is not isothiocyanato when A is --C(O)-amine and W.sub.m is --O--.
When Z.sub.1 and Z.sub.2 are part of a thiophene, furan or pyrrole ring, the novel compounds of the present invention do not include B equal to trimethylsilyl when A is (diethylamino)carbonyl.
The invention also provides fungicidal compositions useful in said method.
As used herein, the term "alkyl", unless otherwise indicated, means an alkyl radical, straight or branched chain, having, unless otherwise indicated, from 1 to 10 carbon atoms. The terms "alkenyl" and "alkynyl" mean unsaturated radicals having from 2 to 7 carbon atoms. Examples of such alkenyl groups include ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-methyl-ethenyl, and the like. Examples of such alkynyl groups include ethynyl, 1-propynyl, 2-propynyl, 1,1-dimethyl-2-propynyl, and so forth. Substituent groups may also be both alkenyl and alkynyl, for example, 6,6-dimethyl-2-hepten-4-ynyl.
As used herein, the term "alkoxy" means an alkyl group having, unless otherwise indicated, from 1 to 10 carbon atoms connected via an ether linkage. Examples of such alkoxy groups include methoxy, ethoxy, propoxy, 1-methylethoxy, and so forth.
As used herein, the term "alkoxyalkyl" means an ether radical having, unless otherwise indicated, from 1 to 10 carbon atoms. Examples of such alkoxyalkyl groups include methoxymethyl, methoxyethyl, ethoxymethyl, ethoxyethyl, and so forth.
As used herein, the terms "monoalkylamino" and "dialkylamino" each mean an amino group having, respectively, 1 or 2 hydrogens replaced with an alkyl group.
As used herein, the term "haloalkyl" means an alkyl radical having one or more hydrogen atoms replaced by halogens, including radicals having all hydrogen atoms substituted by halogen. Examples of such haloalkyl groups are fluoromethyl, difluoromethyl, trifluoromethyl, chloromethyl, trichloromethyl, and so forth.
As used herein, the term "halo" means a radical selected from chloro, bromo, fluoro, and iodo.